1. Field of the Invention
The present invention relates to a writing data processing control apparatus, a writing method, and a writing apparatus. More particularly, for example, the present invention relates to an electron beam writing method by which a target workpiece is irradiated with a variable-shaped electron beam, an electron beam pattern writing apparatus using the method, and a data processing apparatus configuring the electron beam writing apparatus.
2. Description of the Related Art
Microlithography technology which forwards miniaturization of semiconductor devices is extremely important, because only this process performs forming a pattern in semiconductor manufacturing processes. In recent years, with an increase in high integration and large capacity of large-scale integrated circuits (LSI), a circuit line width required for semiconductor elements is becoming narrower and narrower. In order to form a desired circuit pattern on these semiconductor devices, a master pattern (also called a mask or a reticle) with high precision is required. Then, since the electron beam technology for writing or “drawing” a pattern has excellent resolution intrinsically, it is used for manufacturing such high precision master patterns.
FIG. 5 shows a schematic diagram describing operations of a conventional variable-shaped electron beam writing apparatus. The variable-shaped electron beam (EB) pattern writing apparatus operates as follows: As shown in the figure, the pattern writing apparatus includes two aperture plates. A first or “upper” aperture plate 410 has an opening or “hole” 411 in the shape of a rectangle for shaping an electron beam 330. This shape of the rectangular opening may also be a square, a rhombus, a rhomboid, etc. A second or “lower” aperture plate 420 has a variable-shaped opening 421 for shaping the electron beam 330 having passed through the opening 411 of the first aperture plate 410 into a desired rectangle. The electron beam 330 that left a charged particle source 430 and has passed through the opening 411 is deflected by a deflector. Then, the electron beam 330 passes through a part of the variable-shaped opening 421 of the second aperture plate 420, and irradiates a target workpiece 340 mounted on a stage that is continuously moving in a predetermined direction (e.g. X-axis direction) . In other words, a rectangular shape capable of passing through both of the opening 411 and the variable-shaped opening 421 is written in a pattern writing region of the target workpiece 340 mounted on the stage. This method of writing or “forming” a given variable shape by letting beams pass through both of the opening 411 and the variable-shaped opening 421 is called a variable shaped beam (VSB) system.
In the electron beam pattern writing apparatus, during from inputting writing data up to actually shooting a pattern defined by the writing data onto a target workpiece, the data is converted into internal format data according to the specification of the pattern writing apparatus. During this time, parallel processing is performed using a plurality of processing apparatuses in order to reduce the processing time.
Although it is not the processing in the electron beam pattern writing apparatus, a method of generating writing data for the electron beam writing apparatus is disclosed that each processing target region is assigned to a plurality of CPUs at the stage of generating writing data to be input for electron beam writing to perform parallel processing independently (refer to, e.g., Japanese Unexamined Patent Publication No. 6-97058 (JP-A-6-97058)).
As mentioned above, in the electron beam pattern writing apparatus, writing data inputted is converted to internal format data of the pattern writing apparatus by using a plurality of processing devices in which processing is performed in parallel according to the specification of the pattern writing apparatus. If a conversion error occurs in a processing apparatus, to which a certain processing is assigned, in a plurality of processing apparatuses, it becomes impossible to write a desired pattern defined by the writing data. Then, if a user newly performs the conversion processing of the writing data inputted from the first after separating the processing apparatus having the error from the system, it is a loss of time and the writing time will become long.